


Thrust Game

by orphan_account



Category: Undertale (Video Game)
Genre: Begging, Dirty Talk, Ecto-Genitalia (Undertale), Fontcest, Incest, M/M, Overstimulation, Rough Sex, skeleton sex shenanigans
Language: English
Status: Completed
Published: 2018-01-14
Updated: 2018-01-14
Packaged: 2019-03-04 23:52:22
Rating: Explicit
Warnings: No Archive Warnings Apply
Chapters: 1
Words: 1,116
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/13375716
Author URL: https://archiveofourown.org/users/orphan_account/pseuds/orphan_account
Summary: His spine will be out for the night, but they'll laugh about it in the morning.





	Thrust Game

**Author's Note:**

> I realized I never posted this drabble from my Tumblr last year. Due to it's popularity, I decided to post it here, too. Although looking back on it now, this is really stupid.

“ITS FEELS SO DIFFERENT THIS WAY!” Papyrus moans, reaffirming his strong grip on Sans’ ilium crest that continuously bounces away from his hips with every sharp thrust.

Hell, if skeletons could bruise, Sans was sure to find some dark contusions rooting along his sacrum in the morning from Papyrus' unflinching tempo. Every pump of Papyrus’ hips sinks him down deeper into the mattress, each movement timed and precise, drugging him into a carnal, lustful daze.

Sans digs his phalanges into the fabric of the sheets, nearly tearing them from the corners of the mattress in his ecstasy, head whirling from the pleasure. His SOUL is throbbing and pounding in his rib cage, threatening to burst from the bliss; he can’t keep up, patellas impending to give out, but Papyrus’ clutch on the expanse of his ilium crest keeps him grounded. Sans finds some relief by lowing his sternum down to rest on the bed, but strings up his lower half to stay lofting in the air, open and susceptible to Papyrus’ unforgiving assault. He buries his skull into the duvet to contain his whimpers, breaths wet and heavy. He can’t control the saliva drooling from his maw; the dribble embedding deep into the sheets, soaking the surface of the mattress and mingling with the clumps of sweat leaking from his bones.

“ah, ha, pap! p-please” Sans whines.

“TELL ME HOW IT FEELS.”

Sans shakes his skull and chuckles tiredly at Papyrus’ arrogant tone, “good. tight. it hurts a little, but—oh!”

Papyrus slides in with no reprieve, fucking into him deeper as he sucks in a shuddering breath.

It’s so good, and Papyrus shows no sign of stress or strain. Papyrus’ member strikes at all his deep spots, squelching against his quivering walls. His magic is stretched tight around Papyrus’ erection, and he nearly collapses at every bottoming out. His legs are trembling, and the hearty groans that erupt from Papyrus are addicting. It’s so pleasurable that Sans was sure his spine would be out for the night as Papyrus made his point across.

The pressure is building and building at Sans’ groin; he can feel it surging and threatening to burst like a dam.

Sans gasps suddenly when a particularly rough thrust has him sprawling and scrambling for leverage. He clenches his eye sockets shut, nearly blacking out from delirium.

In a flick of a switch, Papyrus relents, body stilling above Sans’ smaller, shaking frame, “ SANS? ARE YOU ALRIGHT? DO YOU NEED TO TAKE A BREAK?” His voice is uncharacteristically soft, lined with earnest concern.

Sans can only slump back against Papyrus hips, taking the moment to recapture some of his stamina.

“…WOULD YOU LIKE ME TO STOP?”

Papyrus’ chest aches with tension and worry, but then he hears a low, wanton moan. He can feel Sans pressing back against him, begging for more. Sans’ magical opening suctions him in deeper until he groans from the tightness circling his cock.

“DOES THAT FEEL GOOD?” Papyrus asks, needing the reassurance to continue.

“…yes,” Sans breathes, voice breaking from desperation.

Hips aching with the need to buck back into Sans’ wet heat, Papyrus takes one more chance to clarify, “MORE?”

“god, yes.”

It’s all the clarification Papyrus needs.

With renewed vigor, Papyrus rams into Sans’ conjured pussy with a grunt. Sans keens sharply, the pressure welling up as though his SOUL is stuck in his throat. The pace is rough, and the room is reduced to nothing but a throb of hot sliding against magic flesh, sounds of fucking and rapture pounding in their skulls.

“o-oh god, i-i can’t, pap! it’s too much!” Tears springs forth from overexertion, and Sans feels himself coming close again.

Papyrus’ cock is twitching and throbbing, and Sans clenches as everything gathers at the center of his body in one, long desperate rush, and he reduces himself to babbling words of encouragement to feel Papyrus’ release shooting deep inside his opening. Eye sockets screwing shut in concentration, Papyrus shoves himself in with one last robust thrust, so hard that pain blossomed at his pelvis and he pulses in orgasm.

…But it’s strange, because while in his thrones of pleasure and through the symphony of Sans’ cries, he is quite certain that he hears some sort of unfamiliar and ambiguously loud snap.

“…uh, bro? a little help.”

Papyrus slowly opens his eye sockets, but then they comically burst in unwarranted surprise when he sees Sans’ skull plopped face first down on the mattress, not attached to his neck. The rest of Sans’ lower half is still stuck up lewdly in the air from Papyrus’ hold, and he can hear Sans’ muffled voice gasping and laughing against the duvet.

“OH NO, OH MY GOD, SANS!” Papyrus exclaims with a shrill, lowering Sans’ stiff pelvis gently on the mattress. He ducks forward to tilt Sans’ skull right side up, and Sans’ eye lights are dancing with humor in their sockets, smile stretching wide. 

“OH MY GOD, OH MY GOD, OH MY GOD!” Papyrus wrings his hands in anxiousness, not sure where to start to find a solution to their rather unconventional problem.

Sans remains completely undeterred, finding the whole situation amusing, “heh, papyrus, relax.”

Papyrus takes a deep breath to calm himself, but to no avail. Grasping his brother’s skull with the upmost care—and completely blocking out Sans’ light murmurs of assuagement in his frantic fumbling—Papyrus quickly scoots back over to the rest of Sans’ abandoned body to reattach the skull to the cord of Sans’ neck.

“SANS, YOU ARE GOING TO BE OKAY! I WILL TAKE CARE OF YOU! JUST UM—“ The small pocket of magic that keeps bones together is slightly fizzled along the top of Sans’ neckbone, and each time Papyrus attempts to stick it back into place, the magic grinds like two magnets rubbing and bouncing off together, as if Sans’ magic is rejecting the insertion.

Releasing a frustrated huff, Papyrus lifts Sans skull in his direction, cradling his brother’s unscrewed head, “WHY ISN’T IT WORKING?”

“eh, it’s probably because my magic is all drained out. just give it a minute and it should pop back on,” Sans snickers, completely burnt out. Papyrus only responds with apprehensive grumble, and he dutifully wipes away the tears that stains the side of Sans’ skull.

“i’ll be fine,” Sans assures; he’s safe here, nothing to stress about. “but, hey, you know…”

Papyrus stiffens in an instant, “SANS, PLEASE DON’T. NOT NOW.”

Sans’ smile only broadens, much to Papyrus’ exasperation, “i guess you could say, i literally came apart in pieces.”

Papyrus allows Sans’ skull to slip from his grasp, plopping back down on the sheets.

They’ll laugh about it in the morning.


End file.
